The present invention relates, in general, to a method for improving a drainage of aqueous humor within the eye of a living being, and to a device for maintaining the improved drainage of aqueous humor.
If the trabecular meshwork is either partially or completely non-functional due to an obstruction or back-up, or pathological changes, natural flow of the aqueous humor becomes limited, thereby raising the pressure inside the eye which negatively impacts on the blood circulation and the function of the visual nerve. The resulting disease is commonly known under the name xe2x80x9cglaucomaxe2x80x9d which may lead to blindness in the eye.
U.S. Pat. No. 5,360,399 describes a method and apparatus, by which the trabecular meshwork, which is located upstream of the Schlemm""s canal and which due to pathological changes, may either partially or completely obstruct the outflow of aqueous humor, is slightly widened by the hydraulic pressure of a highly viscous aqueous solution, which when injected into the Schlemm""s canal opens it at several location points, so that an outflow of the aqueous humor can be realized.
It is thus an object of the present invention to provide an improved method for realizing an enhanced flow of aqueous humor within the eye, obviating the afore-stated drawbacks.
In particular, it is an object of the present invention to provide an improved method by which the necessary drainage of the aqueous humor via the outflow pathways of the eye is realized and which thereby results in an improved circulation of the aqueous humor in the eye for regulating the pressure within the eye.
These objects, and others which will become apparent hereinafter, are attained by a method in accordance with the present invention which includes the following steps: incising a first lamellar section of the sclera to form a first scleral flap; lifting the first scleral flap upwards in the direction of the cornea, thereby creating a recess in the sclera; incising a second lamellar section in the area of the recess to thereby form a second scleral flap and a support surface bounding the scleral flap; lifting the second scleral flap upwards in the direction of the first sclera flap, thereby creating a second recess and exposing a portion of the Schlemm""s canal; implanting in the lumen of the Schlemm""s canal on each of both sides of the second recess, and, optionally, in the exposed portion of the Schlemm""s canal, at least one support element, with each support element being made of a material that is decomposable by the tissue of the Schlemm""s canal and/or the aqueous humor; folding the first scleral flap back, after severance of the second scleral flap, for placement upon the support surface, thereby confining a subscleral space adjacent the first scleral flap; injecting a viscous medium into the subscleral space; and rejoining the first scleral flap to the sclera.
According to another feature of the present invention, the support element is suitably made of biolytically decomposable material and may have a ring-shaped or spherically-shaped configuration or may have an elongate, tubular configuration to hold the lumen in expanded position. The support element may also be formed as a braided mesh of elongate configuration, or as an elongate helical spring.
In accordance with a further feature of the present invention, the second scleral flap can be detached along a portion thereof in the area of the Schwalbe""s line from the partially aqueous humor permeable Descemet""s membrane by applying a slight pressure force to thereby form a gap-shaped opening (window). The detached portion of the second scleral flap can thereby be held in open disposition by protrusions projecting out from the support element, so that the anterior chamber is fluidly connected in the area of the iridocorneal angle via the Descemet""s membrane and the gap-shaped opening with the subscleral space. In this manner, aqueous humor flowing naturally via the trabecular meshwork into the Schlemm""s canal is additionally conducted from the anterior chamber through the partially aqueous humor-permeable Descemet""s membrane and through the gap-shaped opening into the scleral space in fluid communication with the Schlemm""s canal.
It is another object of the present invention to provide an improved device for realizing and maintaining an enhanced flow of aqueous humor within the eye.
This object is attained in accordance with the present invention by providing a support element for implantation into the lumen of the Schlemm""s canal, with the support element having a ring shaped configuration, spherical shaped configuration or tubular shaped configuration, and being made of a decomposable material, in particular of a material that can be decomposed by the tissue of the Schlemm""s canal and/or the aqueous humor.